1. Field of the Invention
The present invention relates to an electrochemical device such as an EDLC (Electric Double Layer Capacitor) as well as to the manufacturing method thereof, a circuit board, and a housing fray,
2. Related Background Art
A conventional flat-type electrochemical device is described, for example, in Japanese Translation of PCT Application No. 2004-515083. With this kind of flat-type electrochemical device, a plurality of leads are extending outward from the inside of an outer package in which the planar shape thereof is a square shape. These leads are generally made of aluminum since they need to satisfy both the resistance properties and electrical conductivity relative to the electrolytic solution, and are electrically connected to an electrode pad using a solder material.
Nevertheless, with a lead made of aluminum, there is a problem in that the fixation strength between the electrode pad and the lead deteriorates since the wettability relative to the solder material is low.